Relevant conflicts of interest/financial disclosures: Lin Zhang, Dina Sukharev, and Andrea Schneider have no financial disclosures. John M. Olichney receives grant support from NIA AG032115. Andreea Seritan receives funding from NIA AG032115. Randi J. Hagerman has received grant support from Seaside Therapeutics, Roche, Johnson & Johnson, Neuropharm, Forest, and the NIH for clinical trials in fragile X syndrome and autism and consults with Novartis regarding treatment of fragile X syndrome. This work was funded by grants from the NICHD (grant HD036071), the NIA (grant AG032115), the NCRR (grant DE019683), and the Health and Human Services Administration of Developmental Disabilities (grant 90DD0596). Full financial disclosures and author roles can be found in the online version of this article.